Lubricating oil



Patented Dec.'19, 1939 UNITED STATES PATENTQFFHCE LUBRICATING OIL Ulric -B. Bray, Palos Verdes Estates, Califi, assigner to Union Oil Company of California, L'os Angeles, Calif., a corporationof California g No Drawing. Application August 2,1937,

Serial No. 156,959

, 7 Claims.

This invention relates to lubricating oils and particularly to light lubricating oils having low pour point.

- The object of the invention is primarily to produce a lubricating oil for use at low temperatures.

. In the ordinary practice of the invention, about 75% of a naphthenic type spray oil is combinedwith about 25% of a highlyparaifinic viscous lubricating oil. For example, where the paraffinic lubricating oil is of the S. A. E. 50 type with a pour point about 15 F., the resultant blend will possessa pour point of around 30 F. below zero; Spray oils of the mentioned classification are those produced from light stocks by heavy solvent treatment such as treatment with liquid sulfur dioxide, accompanied with an additional sulfuric acid treatment,'if required, to yield an oil having a viscosity of about 85 seconds Saybolt Universal at 100 F., a pour point below 50 F. and an unsulfonatable residue of about 90. This unsulfonatable residue value is commonly known as deOng number and is a designation well known in the art for highly refined agricultural spray oils. This value represents that proportion of the oil not subject to sulfonation by a well known sulfonation test described in Industrial and Engineering Chemistry, vol. 18 (1926), page 175. Briefly, the oil is treated with sulfuric acid exactly 37 normal (100%) in a water bath at 95 C. to 100 C.ordinarily at 210 F.--for a 40 period of one hour. The above acid is added to the oil in proportions of 20 c. c. of acid to 5 c. c. 1 of oil in two dumps in aBabcock cream test bottle, the mix being agitated every 10 minutes. After phase separation, the unsulfonated material is the unsulfonatable residue, the percentage of which constitutes the test for the oil and is often called deOng number.

The highly paraifinic lubricating oil indicated may be one produced by heavy solvent treatment of Mid-Continent paraffinic type oils or other paraffinic stocks to yield very highly parafiinic lubricating oil fractions from which (following dewaxing) all aromatic and other readily reactive materials are removed by the solvent treatment. This form of treatment is now well known and v (Li includes treatment with such solvents as liquid sulfur dioxide-benzol mixtures, furfural, phenol, cresol, dichlorethyl ether and the like.

Also a corresponding Pennsylvania Bright Stock sometimes may be used as the lubricating oil fraction F 5 product had a viscosity index of about 92, high 10 stability and aviscosity of about 150 seconds or less Saybolt Universal at 100 F.

Instead of employing of spray oil and 25% of lubricating oil, the proportions may be varied as desiredto attain the resultant physical 15 characteristics required. For example, the content'of a highly paraffinic lubricating material may be somewhat reduced, or if an oil of higher pour point is permitted, it may be increased, for example to equal parts of the two constituents;

Instead of employing the highly refined paraffinic lubricating fraction mentioned (S. A. E. 50), a similar fraction of higher or lower viscosity may be employed, the proportion of spray oil being correspondingly modified, that is, being increased 25 as the parafiinic lubricating oil grade is heavier, or decreased as the lubricating oil is lighter, where a product of the same viscosity is required.

The oil blends of this invention may also contain a so-called oiliness agent, to increase film 30 strength and impart wear resistant qualities. Such agents are commonly chlorinated organic materials having boiling points high enough to avoid being boiled off in the crank cases of internal'combustion engines. These materials may 35 be added in amounts from about 0.5% to 4% or 5%, e. g. 1%. Suitable such substances include methyl dichlorstearate or palmitate, ethyl dichlormargarate, chlorinated paraffin, chlorinated diphenyl oxide, methyl chloronaphthenate and 40 other kindred chlorinated compounds. Sulfur compounds may be used sometimes for the same purpose such as sulfurized sperm oil or lard oil, and phosphorous bearing materials such as tricresyl phosphate. agents may be added where necessary or desirable. This type of material is known for this purpose and is representedby a group of condensation products of aromatic hydrocarbons (ring compounds) with chlorinated long chain 50 aliphatic hydrocarbons, produced in the presence of a metallic halide by the Friedel-Crafts catalytic reaction. The chain compounds may be paraflin, petrolatum, montan wax and other heavy hydrocarbons, and the ring compounds 55 Also, pour point depressing may be naphthalene, anthracene, diphenyl and the like as disclosed by Davis No. 1,815,022, MacLaren No. 1,963,917 and No. 1,963,918 and other patents. Such materials are added to the lubricating oil in small amounts such as from 0.2% or 0.3% to perhaps as much as 4% or 5%, ordinarily about 0.8% to 1%, according to the effect desired or the character of the lubricating oil stock used, i. e., wax content thereof.

It is to be understood that these disclosures are merely illustrative of the generic invention and are not to be taken as limiting.

I claim:

1. A lubricating oil comprising as important constituents a large proportion based on the total composition of a highly refined mineral spray oil 'having a high deOng number and low viscosity,

and a highly refined parafiinic viscous lubricating oil fraction of relatively greater viscosity.

2. A mineral lubricating oil of low pour point comprising a highly refinedlow viscosity mineral spray oil approximating 50% or more of the composition, and a highly refined highly parafiinic a Saybolt Universal viscosity at 100 F. not exceeding about 150 seconds.

5. A lubricating oil of low pour point comprising as principal constituents large proportions based on the total composition of each of highly refined mineral spray oil fractions and highly refined highly paraflinic viscous mineral lubricating oil fractions, the blend having a pour point below F.

,6. A low pour point mineral lubricating oil comprising as principal constituents a highly refined, viscous, paraflinic type lubricating oil fraction and a large proportion based on the total composition of a highly refined low viscosity naphthenic mineral oil having a high unsulfonatable residue, a viscosity in the order of about 85 seconds Saybolt Universal at 100 F., and a pour point at least as low as about minus 50 F., the blend having a pour point at least as low as about minus 30 F.

I. A low pour point mineral lubricating oil comprising as principal constituents highly refined paraifmic viscous mineral lubricating oil 

